Days Until Harvest: 55 Brassica Oleracea Heirloom vegetable This kale variety is an extremely vigorous. Produces Smooth leaves with scalloped edges 55 Days. This kale variety is an extremely vigorous. The Outside leaves can be snapped off and bunched, and the center will re grow. Premier Kale is a slow bolting variety that is best suited to cooler climates. Produces Smooth leaves with scalloped edges, Ideal for juicing and healthy smoothies.